Battery Pack

ABSTRACT

Disclosed is a battery pack including a battery module having a plurality of battery cells, and a heat dissipation member provided in contact with a bus bar at a side surface of the battery module where electrode leads of the battery cells and the bus bar coupled to the electrode leads are disposed.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is national phase entry under 35 U.S.C. § 371 ofInternational Application No. PCT/KR2018/013741 filed Nov. 12, 2018,which claims priority to Korean Patent Application No. 10-2017-0164084filed on Dec. 1, 2017 in the Republic of Korea, the disclosures of whichare incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a battery pack, and more particularly,to a battery pack capable of improving heat dissipation efficiency.

BACKGROUND ART

As technology development and demand for a mobile device have increased,demand for a secondary battery as an energy source has rapidlyincreased.

Conventionally, a nickel-cadmium battery or a hydrogen ion battery hasbeen used as the secondary battery. However, a lithium secondary batteryis recently widely used because charging and discharging is free due torare memory effect in comparison with a nickel-based secondary battery,a self-discharge rate is very low, and an energy density is high.

The lithium secondary battery mainly uses a lithium oxide and acarbonaceous material as a positive electrode active material and anegative electrode active material, respectively. The lithium secondarybattery includes an electrode assembly in which a positive electrodeplate and a negative electrode plate, respectively coated with thepositive electrode active material and the negative electrode activematerial, are arranged with a separator therebetween, and an outermember, that is a battery case, which seals and receives the electrodeassembly together with an electrolyte solution.

The lithium secondary battery includes a positive electrode, a negativeelectrode, and a separator interposed therebetween and an electrolyte.Depending on which material is used for the positive electrode activematerial and the negative electrode active material, the lithiumsecondary battery is classified into a lithium ion battery (LIB) and apolymer lithium ion battery (PLIB). Generally, an electrode of thelithium secondary battery may be prepared by applying the positive ornegative electrode active material to a current collector made ofaluminum or copper sheet, mesh, film, foil, or the like and then dryingthe same.

FIG. 1 is a schematic exploded perspective view showing a conventionalbattery pack, FIG. 2 is a schematic perspective view showing theconventional battery pack, and FIG. 3 is a schematic cross-sectionedview, taken along the line A-A′ of FIG. 2.

Referring to FIGS. 1 to 3, a conventional battery pack 1 includes abattery module 2. In the battery module 2, based on FIG. 1, a thermalpad 4 and a heatsink 5 are sequentially coupled to a bottom portion 3 toemit heat generated from the battery module 2. However, a region of thebattery cell where heat is generated most is an electrode lead or a busbar 6 directly connected to the electrode lead, rather than a bottomsurface of the battery cell. Thus, even though the thermal pad 4 and theheatsink 5 are coupled to the bottom portion 3 of the battery module 2where battery cells are stacked, the heat dissipation efficiency is nothigh. In FIGS. 1 and 2, the reference sign 7 designates a lower tray.

Also, as in FIG. 3, the thermal pad 4 and the heatsink 5 are coupled tothe bottom portion 3 of the battery module 2. Thus, the total height ofthe battery pack 1 accommodating the plurality of the battery modules 2is increased as much as the thickness of the thermal pad 4 and theheatsink 5.

In addition, as in FIG. 1, the thermal pad 4 and the heatsink 5 aremanufactured to have a size corresponding to the total size of thebottom portion 3 of the battery module 2. Thus, the thermal pad 4 andthe heatsink 5 should have a large area, which increases the cost.

SUMMARY Technical Problem

The present disclosure is directed to providing a battery pack, whichmay improve the heat dissipation efficiency through a structural change.

Also, the present disclosure is directed to providing a battery pack,which may have a reduced total thickness.

In addition, the present disclosure is directed to providing a batterypack, which may require a reduced cost to manufacture a heat dissipationmember.

Technical Solution

In one aspect of the present disclosure, there is provided a batterypack, comprising: a battery module having a plurality of battery cells;and a heat dissipation member provided in contact with a bus bar at aside surface of the battery module where electrode leads of theplurality of battery cells and the bus bar coupled to the electrodeleads are disposed

Also, the battery module may include a plurality of battery modules,each battery module having a plurality of battery cells and a sidesurface where electrode leads of the plurality of battery cells and thebus bar coupled to the electrode leads are disposed. The plurality ofbattery modules may be provided in a single layer and arranged in atleast one row or column.

In addition, the heat dissipation member may have a cavity formedtherein whereby the plurality of battery modules are disposed in thecavity, and the heat dissipation member surrounds the side surface ofeach of the plurality of battery modules.

Also, the heat dissipation member may have a band shape to surround rimsof the plurality of battery modules, and the heat dissipation member maybe provided in contact with the bus bar.

In addition, the heat dissipation member may include: a thermal padcoupled to the bus bar at the side surface of the battery module, and aheatsink coupled to the thermal pad.

Also, the heat sink may be configured to form a flow path so that afluid for cooling flows therethrough.

In addition, the heat dissipation member may have a height correspondingto a height of the side surface of the battery module.

Meanwhile, in another aspect of the present disclosure, there is alsoprovided a vehicle, comprising the battery pack of any of theembodiments described herein.

In another aspect of the present disclosure, there is provided a heatdissipation apparatus for dissipating heat generated by a battery modulehaving a plurality of cells. The heat dissipation apparatus includes aheat dissipation member provided in contact with a bus bar of thebattery module at a side surface of the battery module where electrodeleads of the plurality of battery cells and the bus bar coupled to theelectrode leads are disposed.

Advantageous Effects

In the embodiments of the present disclosure, since the heat dissipationmember is in direct or indirect contact with an electrode lead or a busbar directly connected to the electrode lead where heat is emittedrelatively greater, rather than to a bottom portion of the batterymodule where heat is emitted relatively smaller, it is possible toimprove the heat dissipation efficiency.

Also, since the thermal pad and the heatsink are coupled to the sidesurface of the battery module, rather than to the bottom portion of thebattery module, it is possible to reduce the total height of the batterypack.

In addition, since the heat dissipation member is coupled to the batterymodule only at the side surface, the total area of the heat dissipationmember is decreased, thereby reducing the cost of manufacturing the heatdissipation member.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic exploded perspective view showing a conventionalbattery pack.

FIG. 2 is a schematic perspective view showing the conventional batterypack.

FIG. 3 is a schematic cross-sectioned view, taken along the line A-A′ ofFIG. 2.

FIG. 4 is an exploded perspective view showing a battery pack accordingto the first embodiment of the present disclosure.

FIG. 5 is a perspective view showing the battery pack according to thefirst embodiment of the present disclosure.

FIG. 6 is a schematic cross-sectioned view, taken along the line B-B′ ofFIG. 5.

FIG. 7 is a schematic perspective view showing that a heat dissipationmember is coupled to a side surface of a battery module, at the batterypack according to the first embodiment of the present disclosure.

FIG. 8 is a schematic cross-sectioned view, taken along the line C-C′ ofFIG. 7.

FIG. 9 is a schematic perspective view showing that a heat dissipationmember is coupled to a side surface of a battery module, at a batterypack according to the second embodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, preferred embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings. Priorto the description, it should be understood that the terms used in thespecification and the appended claims should not be construed as limitedto general and dictionary meanings, but interpreted based on themeanings and concepts corresponding to technical aspects of the presentdisclosure on the basis of the principle that the inventor is allowed todefine terms appropriately for the best explanation. Therefore, thedescription proposed herein is just a preferable example for the purposeof illustrations only, not intended to limit the scope of thedisclosure, so it should be understood that other equivalents andmodifications could be made thereto without departing from the scope ofthe disclosure.

In the drawings, the size of each element or a specific part of theelement may be exaggerated, omitted, or schematically illustrated forconvenience and clarity of a description. Thus, the size of each elementdoes not entirely reflect the actual size of the element. A detaileddescription of well-known functions or elements associated with thepresent disclosure will be omitted if it unnecessarily obscures thesubject matter of the present disclosure.

The term, ‘combine’ or ‘connect’ as used herein, may refer not only to acase where one member and another member are directly combined ordirectly connected but also a case where one member is indirectlycombined with another member via a connecting member or is indirectlyconnected.

FIG. 4 is an exploded perspective view showing a battery pack accordingto the first embodiment of the present disclosure, FIG. 5 is aperspective view showing the battery pack according to the firstembodiment of the present disclosure, FIG. 6 is a schematiccross-sectioned view, taken along the line B-B′ of FIG. 5, FIG. 7 is aschematic perspective view showing that a heat dissipation member iscoupled to a side surface of a battery module, at the battery packaccording to the first embodiment of the present disclosure, and FIG. 8is a schematic cross-sectioned view, taken along the line C-C′ of FIG.7.

Referring to FIGS. 4 to 8, a battery pack 10 according to the firstembodiment of the present disclosure includes a battery module 100 and aheat dissipation member 200. In FIGS. 4 and 5, the reference sign 300designates a lower tray.

In the battery pack 10, a plurality of battery modules 100 may bestacked or arranged in various ways. However, for convenience ofexplanation, it will be assumed that the plurality of battery modules100 are provided in a single layer and arranged in at least one row orcolumn Here, the ‘row’ means the X direction based on FIG. 4, and the‘column’ means the Y direction based on FIG. 4. In the first embodiment,the battery modules 100 are arranged in one row and six columns. If theplurality of battery modules 100 are provided in a single layer asdescribed above, the battery modules 100 may be easily disposed in aspace with a limited height, such as an underfloor of an electricvehicle or the like. However, the use of the battery pack 10 accordingto the first embodiment of the present disclosure is not limited to avehicle or the like.

The battery pack 10 may include an upper case (not shown) and a packcover (not shown), and the upper case may be coupled to the pack coverto accommodate and protect the plurality of the battery modules 100. Theupper case and the pack cover may accommodate one battery module 100 ora plurality of battery modules 100. That is, at least one battery module100 is arranged inside the upper case and the pack cover so that theupper case and the pack cover surround and protect the battery module100. Namely, the upper case and the pack cover entirely enclose thebattery module 100, thereby protecting the battery module 100 againstexternal vibration or shock. The upper case and the pack cover may beshaped corresponding to the shape of the battery module 100. Forexample, if the entire shape of the battery modules 100 arranged in asingle layer is a hexahedron shape, the upper case and the pack covermay be provided in a hexahedron shape to correspond thereto. The uppercase and the pack cover may be fabricated, for example, by bending ametal plate, and thus the upper case and the pack cover may befabricated in an integrated form. Here, if the upper case and the packcover are integrally fabricated, the coupling process may be performedin a simple and convenient way. Alternatively, the upper case and thepack cover may be fabricated separately and coupled together usingvarious methods such as welding, riveting, bolt, bolting, pin coupling,bracketing, moment bonding or the like. In addition, the battery pack 10may include various devices for controlling charge and discharge of thebattery module 100, such as a battery management system (BMS), a currentsensor, a fuse, and the like.

The battery module 100 includes a plurality of battery cells 110. Thebattery cell 110 may be configured so that a plurality of unit cells, ineach of which a positive electrode plate, a separator and a negativeelectrode plate are arranged in order, or a plurality of bi-cells, ineach of which a positive electrode plate, a separator, a negativeelectrode plate, a separator, a positive electrode plate, a separatorand a negative electrode plate are arranged in order, are stackedsuitable for a battery capacity. In addition, the battery cell 110 (seeFIG. 6) may include an electrode lead 111 (see FIG. 8). The electrodelead 111 is a kind of terminal exposed to the outside and connected toan external device and may be made of a conductive material. Here, theelectrode lead 111 may be electrically coupled to a bus bar 120 (seeFIG. 8). FIG. 4 schematically shows that the bus bar 120 is coupled tothe electrode lead 111, and the bus bar 120 made of a conductive metalmay have a frame function together. Alternatively, a frame made of ametal may be coupled to the bus bar 120 and the heat dissipation member200 may be coupled to the frame such that the heat dissipation member200 is indirectly coupled to the bus bar 120 by means of the frame. Theelectrode lead 111 may include a positive electrode lead and a negativeelectrode lead. The positive electrode lead and the negative electrodelead may be disposed at opposite sides of the battery cell 110 in thelongitudinal direction, or the positive electrode lead and the negativeelectrode lead may be disposed at the same side the battery cell 110 inthe longitudinal direction. Meanwhile, the battery module 100 mayinclude a plurality of cartridges for accommodating the battery cells110. Each cartridge may be fabricated by injection-molding plastic, anda plurality of cartridges having an accommodation portion foraccommodating the battery cell 110 may be stacked. A cartridge assemblyin which a plurality of cartridges are stacked may include a connectorelement or a terminal element. The connector element may include varioustypes of electrical connecting components or connecting members forconnecting to, for example, a battery management system (BMS) (notshown) capable of providing data on voltage or temperature of thebattery cells 110. In addition, the terminal element includes a positiveelectrode terminal and a negative electrode terminal as main terminalsconnected to the battery cell 110, and the terminal element may have aterminal bolt to be electrically connected to the outside.

Referring to FIGS. 4, 5 and 7, the heat dissipation member 200 is incontact with the bus bar 120 provided to the battery module 100 at aside surface of the battery module 100. The side surface of the batterymodule 100 means a portion of the battery module 100, where theelectrode lead 111 protrudes and is coupled to the bus bar 120, namelywhere the electrode lead 111 is coupled to the bus bar 120, when thebattery module 100 is arranged as in FIG. 4.

As shown in FIG. 4, the heat dissipation member 200 may have a hollow230 formed therein, and the battery modules 100 may be disposed in thehollow 230 of the heat dissipation member 200. Also, the heatdissipation member 200 having the hollow 230 may be formed to surroundthe side surfaces of the plurality of battery modules 100 (see FIGS. 5and 7). In addition, the heat dissipation member 200 may have a bandshape as shown in FIG. 4. If the heat dissipation member 200 is formedin a band shape as described above, the heat dissipation member 200contacts the bus bar 120 while surrounding the entire rim of theplurality of battery modules 100, and thus the heat generated from thebattery cells 110 may be directly emitted by the heat dissipation member200 through the electrode leads 111 and the bus bar 120.

The heat dissipation member 200 may include a thermal pad 210 and aheatsink 220. The thermal pad 210 may be coupled to the bus bar 120 atthe side surfaces of the plurality of battery modules 100, and theheatsink 220 may be coupled to the thermal pad 210 (see FIG. 8). Due tothe thermal pad 210 coupled to the bus bar 120 and the heatsink 220coupled to the thermal pad 210, the heat generated within the batterycells 110 may be directly emitted through the bus bar 120.

The heat dissipation member 200 may have a height corresponding to theheight of the side surface of the battery module 100. That is, theheight of the side surface of the battery module 100 and the height ofthe bus bar 120 may be substantially the same, and the height of theheat dissipation member 200, namely the thermal pad 210 and the heatsink220, may be substantially equal to the height of the bus bar 120.However, the present disclosure is not necessarily limited thereto, andan appropriate height may be selected as necessary.

The heatsink 220 of the heat dissipation member 200 may have a flow path221 through which a fluid for cooling flows, as shown in FIG. 8. Inaddition, referring to FIG. 4, the heatsink 220 may have an inlet 222through which the fluid flows in and an outlet 223 through which thefluid flows out. The fluid introduced through the inlet 222 flows alongthe flow path 221 formed at the heatsink 220 and is discharged outthrough the outlet 223 (see the arrow L in FIG. 7). While the fluidflows along the flow path 221, heat is transferred to the thermal pad210 coupled to the heatsink 220.

As described above, the region of the battery cell 110 where heat isgenerated most is the electrode lead 111 or the bus bar 120 directlyconnected to the electrode lead 111, rather than the bottom surface ofthe battery cell 110. Thus, if the heat dissipation member 200 of thebattery pack 10 according to the first embodiment of the presentdisclosure is coupled to the bus bar 120 at the side surfaces of thebattery modules 100, the heat dissipation efficiency is greatlyenhanced, compared to the conventional case where the heat dissipationmember 200 is coupled to the bottom portion of the battery module 100.In addition, since the heat dissipation member 200 is formed in a bandshape to contact only the side surface of the battery module 100, thearea of the heat dissipation member 200 is significantly reducedcompared to the conventional heat dissipation member 200 that contactsthe entire bottom of the battery module 100, thereby reducing themanufacturing cost. Also, referring to FIG. 6, since the heatdissipation member 200 is not coupled to the bottom portion of thebattery module 100 but is coupled to the side surface of the batterymodule 100, the overall height of the battery pack 10 may be reducedcompared to the conventional case of FIG. 3.

Hereinafter, the operations and effects of the battery pack 10 accordingto the first embodiment of the present disclosure will be described.

The plurality of battery modules 100 may be provided in a single layerand arranged in at least one row or column. At this time, the electrodelead 111 of the battery cell 110 and the bus bar 120 coupled to theelectrode lead 111 are disposed at the side surface of the batterymodule 100. The heat dissipation member 200 may include the thermal pad210 and the heatsink 220. The heat dissipation member 200 may have thehollow 230 formed therein and be formed in a band shape to surround theside surfaces of the battery modules 100. In addition, the thermal pad210 is in contact with each bus bar 120 located at the side surfaces ofthe battery modules 100, and the heatsink 220 is coupled to the thermalpad 210. The flow path 221 is formed inside the heatsink 220, and thefluid exchanges heat with the thermal pad 210 while moving along theflow path 221 inside the heatsink 220. As a result, the heat generatedat the battery cell 110 may be emitted while moving to the thermal pad210 and the heatsink 220 through the electrode lead 111 and the bus bar120.

FIG. 9 is a schematic perspective view showing that a heat dissipationmember is coupled to a side surface of a battery module 100, at abattery pack 10 according to the second embodiment of the presentdisclosure.

Hereinafter, the operations and effects of the battery pack 10 accordingto the second embodiment of the present disclosure will be describedwith reference to the accompanying drawings. Here, a feature alreadyexplained in relation to the battery pack 10 according to the firstdisclosure of the present disclosure will not be described in detailagain.

In the second embodiment of the present disclosure, the battery modules100 are arranged in a plurality of rows and a plurality of columns andcoupled to the heat dissipation member 200, different from the firstembodiment where the battery modules are arranged in one row and aplurality of columns.

That is, even though the battery modules 100 are arranged in one row andsix columns in the first embodiment, in the second embodiment, thebattery modules 100 are arranged in two rows and six columns. Meanwhile,the number of rows and columns of the battery modules 100 may be varied,and in some cases, one battery module 100 arranged in one row and onecolumn may be included in one battery pack 100.

Referring to FIG. 9, the battery modules 100 are arranged in two rowsand six columns. In addition, the heat dissipation member 200 may bebent between the battery module 100 in the first row and the batterymodule 100 in the second row to contact both the battery module 100 inthe first row and the battery module 100 in the second row. Here, thefluid introduced through the inlet 222 flows along the flow path 221formed in the heatsink 220 and is discharged out through the outlet 223(see the arrow M in FIG. 9). Referring to FIG. 9, one heat dissipationmember 200 is provided to surround both the battery module 100 in thefirst row and the battery module 100 in the second row. By doing so, thenumber of inlets 222 and outlets 223 may be reduced, compared to thecase where two heat dissipation members 200 are provided to surround thebattery module 100 in the first row and the battery module 100 in thesecond row individually. However, if necessary, two heat dissipationmembers 200 may be provided to surround the battery module 100 in thefirst row and the battery module 100 in the second row individually.

Meanwhile, a vehicle (not shown) according to an embodiment of thepresent disclosure may include the battery pack 10 described above, andthe battery pack 10 may include the battery module 100. In addition, thebattery pack 10 according to the first and second embodiments of thepresent disclosure may be applied to the vehicle (not shown), forexample a vehicle using electricity such as an electric vehicle or ahybrid electric vehicle.

The present disclosure has been described in detail. However, it shouldbe understood that the detailed description and specific examples, whileindicating preferred embodiments of the disclosure, are given by way ofillustration only, since various changes and modifications within thescope of the disclosure will become apparent to those skilled in the artfrom this detailed description.

INDUSTRIAL APPLICABILITY

The present disclosure relates to a battery pack and is particularlyapplicable to an industry related to a secondary battery.

1. A battery pack, comprising: a battery module having a plurality ofbattery cells; and a heat dissipation member provided in contact with abus bar at a side surface of the battery module where electrode leads ofthe plurality of battery cells and the bus bar coupled to the electrodeleads are disposed.
 2. The battery pack according to claim 1, comprisinga plurality of battery modules, each battery module having a pluralityof battery cells and a side surface where electrode leads of theplurality of battery cells and the bus bar coupled to the electrodeleads are disposed, wherein the plurality of battery modules areprovided in a single layer and arranged in at least one row or column.3. The battery pack according to claim 2, wherein the heat dissipationmember has a cavity formed therein, wherein the plurality of batterymodules are disposed in the cavity, and wherein the heat dissipationmember surrounds the side surface of each of the plurality of batterymodules.
 4. The battery pack according to claim 3, wherein the heatdissipation member has a band shape to surround rims of the plurality ofbattery modules, and wherein the heat dissipation member is in contactwith the bus bar.
 5. The battery pack according to claim 1, wherein theheat dissipation member includes: a thermal pad coupled to the bus barat the side surface of the battery module; and a heatsink coupled to thethermal pad.
 6. The battery pack according to claim 5, wherein theheatsink is configured to form a flow path so that a fluid for coolingflows therethrough.
 7. The battery pack according to claim 1, whereinthe heat dissipation member has a height corresponding to a height ofthe side surface of the battery module.
 8. A vehicle, comprising abattery pack according to claim
 1. 9. A heat dissipation apparatus fordissipating heat generated by a battery module having a plurality ofcells, the heat dissipation apparatus comprising a heat dissipationmember provided in contact with a bus bar of the battery module at aside surface of the battery module where electrode leads of theplurality of battery cells and the bus bar coupled to the electrodeleads are disposed.